Neutralized tube transmitting apparatus



May 23, 1933. oc ow 1,910,814

NEUTRALIZED TUBE TRANSMITTING APPARATUS Filed April 3, 1931 Z, 3 W? l M Ag A717- 2 32 T f, f;

Patented May 23, 1933 UNITED STATES ATENT; o 'F cE Hans nocnow, OF BERLIN-TEMPELHOF, GERMANY,- essrenon rojornonnnz AK'IIENGESELLSCHAFT, or BERLIN-TEMPELHOF, GERMANY- I NEUTBALIZED TUBE rnansiarr'rine arrAn-aros Application filed April 3, 1931, Serial No.

Neut 'alized tube transmitting apparatus often olfer difficulties in that the neutralizing condensers fail in the requisite constancy of the capacity. As condensers of this type frequently oil condensers are used, the dielectric 0111 the anode volt-a e of continuous current but also the alternating current voltage is in eixstence. In order to attain as high a safety against sparking over as possible it is necessary to make use of great distances of the plates. But as through the great distance of the plates the magnitude of the capacity will be reduced, it is necessary for the sake of compensation to increase the superficial area of the plates. Through the increases of the surface of the plates, however, the capacity of space, that is the capacity between the plates and the remaining structure of the transmitting apparatus and earth respectively, will become very great at the same time.

But such increase must be avoided particularly with short waves in the interest of a faultless construction of the whole transmitting apparatus.

In order to avoid the deficiencies referred to according to the invention it is suggested to bridge the variable neutralizing condenser tor the continuous current voltage by means of a resistance. In order to be able to carry through such arrangementit is also necessary to divide the neutralizing condenser into a stationary and a variable part and to connect the bridging resistance to the point of junction of the stationary and variable condenser.

A practical arrangement of the device according to the invention is shown by way of example in the diagrammatic drawing.

The idea of the invention may best be explained with reference to the drawing, illus- 527,415, and inl Germany Apri1 28, 1930.

trating diagrammatically by way of example a neutralized counter-tlmestep. Both tubes or valves It, and R5 are connected on the side of the anode with the inductance L while hand is connected to the cathodes of the tubes by way of the condenser C and on the other hand with a central tapping of the inductance L i The neutralization is effected with the aid of both variable neutralizing condensers h", and N connected in series with both stationary i'leutralizing condensers F and F Owing to this successive connection of the condensers N and F and N and F respectively the alternating current voltage will thus be divided in a corresponding manner. At the points 1 and 2 there is connected a resistance VV or VV respectively, one end of which leads to the point 3. The latter is in connection with the positive pole of the source An for the anode current. Disregarding the continuous current resistance of the inductance L the point 3 shows the same potential of continuous current as the plates of the variable neutralizing condensers N and N at the side of the anode. As in the resistances IV, and Wlll flow no contmuous current and in consequence no drop of voltage can be caused, the same continuous current volt- ,7

age must prevail at the points 1 and 2 as at point 3 and the anodes. In this manner the arrangement according tothe invention ensures, that the same continuous current volt age is present on both sides of the variable neutralizing condensers, in other words that these condensers are bridged for the continuous current voltage. The alternating currentvoltage present at such a condenser is at the same time reduced through the condenser F, or F respectively likewise connected.

lVith this arrangement the variable condenser may be of small dimensions and the capacity of space can be rendered slight. The stationary condensers proper possess already a small capacity of space, since mica may be selected for these, which material possesses a higher dielectric constant and resistance power against puncturing than air.

I claim:

1. Neutralized tube transmitting apparatus of the character described comprising in combination a variable neutralizing c'ondenser and means for bridging the latter'in respect of continuous current voltage.

2. Neutralized tube transmitting apparatus of the character described comprising in combination a variable neutralizing condenser, connected in series with a stationary condenser and means for bridging the said variable condenser in respect of continuous current voltage.

3. Neutralized tube transmitting apparatus of the character described comprising in combination a variable neutralizing condenser and a resistance adapted for bridging said variable neutralizing condenser.

4. Neutralized tube transmitting apparatus of the character described comprising in combination a variable neutralizing condenser, connected in series with a stationary condenser and a resistance adapted for bridging the said variable condenser.

In testimony whereof I aflix my signature.

HANS ROOHOW. 

